Traction-tire.



h 0. STEPHENS.

TRAGTION TIRE. APPLIOATION FILED AUG. 29, 190B.

Patented June 15, 1909.

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' TOR I I l I. Allornays.

CLARK STEPHENS, OF PINKSTAFF, ILLINOIS.

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Specification of Letters Patent.

Patented June 15, 1909.

. Application filed August 29, 1908. Serial No. 450,863.

To all whom it may concern:

Be it known that I, CLARK Srnrnnxs, a citizen of the United States, andresident of Pinkstafl, Lawrence county, State of Illinois, have inventedcertain new and useful Improvements in Traction-Tires; and my preferredmanner of carrying out the invention is set forth in the following full,clear, and exact description, terminating with claims particularlyspecifying the novelty.

This invention relates to traction wheels in the class of carriages andwagons, and

more particularly it is a tire adapted for use on the driving wheels oflawn mowers and the like to prevent them from slipping. It is well knownthat when such machines are driven along a side hill they often sliplaterally out of the path through which it is desired they shall travel.It is also well known that the cutting mechanism on a lawn mower isdriven at a high rate of speed by its supporting wheels, and especiallywhere the grass is coarse or dense the resistance aiforded frequentlycauses said wheels to slip rather than to turn as they must in order todrive the cutting mechanism.

One object of this invention is to produce a traction wheel-or a tirewhich may be applied to the rim of an ordinary wheel that will avoidsuch slipping both laterally and longitudinally.

To these ends the invention consists specifically in the traction wheeltire hereinafter more fully described and claimed, and shown in theaccompanying drawings wherein- Figure 1 is a side elevation of a portionof a lawn mower with my improved tract-ion tire applied to its nearestwheel; Fig. 2 is a plan view of the tire showing the initial cut formaking a tooth and Fig. 3 is an edge view thereof. Fig. a is a plan viewof a section of the tire showing two of the teeth as bent upward; andFig. 5 is a section on the line 55 of Fig. 4-.

In the drawings the letter H designates the handle of a lawn mower whosemachinery further than this is not illustrated, and S the main shaft onwhich is mounted the wheels W of which only the nearest one is shown.These wheels may be of iron with a metal rim, and the rim itself may betreated as hereinafter described; they may be of wood or other material,and the tire described below can be shrunk or otherwise secured aroundthem; or they may, in fact, be of metal, and the the below can be shrunkor otherwise secured thereon. The details thus far described form nopart of the present invention, and are illustrated and described tobring out the preferable use of my improved traction tire. This tire Mis made from a strip of metal such as iron, preferably about an inchwide and one eighth of an inch thick. Along one edge, which is to be theouter edge or corner of either wheel, are first cut kerfs K as by theuse of a cold chisel, as seen in Figs. 2 and 3.

'lransversely of the metal strip each kerf inclines forward laterally toits front end F so that the kerf occupies an oblique position when seenin plan view, and radial of the complete tire each kerf inclines forwardtoward its inner edge I as seen in Fig. 3, so that when viewed in planit appears to be undercut. That part of the metal at the edge of thestrip M which is bounded by the acute angle formed by the kerf is thenbent upward or radially outward on the dotted line D of Fig. 2 so as toproduce triangular teeth T as seen in Fig. 4:, each extending from apoint P coincident with the outer edge of the strip M obliquely rearwardand inward to the point A which is the acute angle formed by the kerf K.In so bending the teeth outward their bodies and their rear undercutends are made to stand in a plane at right angles to the strip M at thatpoint, and their rear ends from the points A to F will be inclined tothe rear around the wheel to just the extent that the kerf K *asinclined forward when it was cut. Said rear ends will also be slightlybeveled to just the extent that said kerf was undercut. Finally, Ipreferably swage the teeth so that they are a little thinner along theirouter edges than attheir inner edges where their bodies merge into thestrip M on the curved line C, although this I do not consider essential.

A traction tire as thus constructed is attached to or shrunk on eachwheel V of the lawn mower, with the teeth along its outer corner asshown in Fig l, and at each revolution of the wheel the thinner edges ofthe teeth embed the sod to an extent dependent upon the weight of themachine and the vigor with which it is propelledthereby preventinglateral slipping. It is obvious that a forward impulse on the handle Hpushes the machine both downward and forward and more deeply embeds theteeth whose wider beveled ends therefore cut into the sod and preventslipping of the wheels under the resistance set up by the machineryflat, the kerf K will not be undercut as shown at I. If it is preferredto have its rear end strictly radial to the wheel, the kerf K will notbe inclined forward but will be cut straight across the strip M.

Either modification of the structure may be employed without the other,but I consider the preferred form of this tire to be that shown anddescribed.

What is claimed as new is:

1. A traction tire consisting of a metal strip having integraltriangular teeth out fromone of its edges and each bent outward from itinto a plane substantially at right angles to the axis ofthe tire.

2. A traction tire consisting of a metal strip having integraltriangular teeth cut from one of its edges and each bent outward from itinto a plane substantially at right angles to the axis of the tire, thelines of the bends being and the teeth standing oblique to the line oftravel.

8. A traction tire having radially projecting teeth extending nearly ina line with each other around its periphery with their rear endsbeveled.

l. A traction tire having radially proj ecting teeth extending nearly ina line with each other around its periphery with their rear endsinclined outward to the rear of a radius.

5. A traction tire having radially projecting teeth extending nearly ina line with each other around its periphery with their rear ends beveledand inclined outward to the rear of a radius.

6. A traction tire having triangular teeth bent outward from one of itsedges at their wider ends and merging into said edge at their narrowerends.

7. A traction tire having triangular teeth bent outward from one of itsedges at their wider ends and merging into said edge at their narrowerends their bodies growing thinner from their bends to their outer edges.

8. A traction tire having triangular teeth bent outward from one of itsedges at their wider ends and merging into said edge at their narrowerends, their rear ends being beveled. I

9. A traction tire having triangular teeth bent outward from one of itsedges attheir wider ends and merging into said edge at their narrowerends, their rear ends being inclined to the rear of a radius.

10. A traction tire having triangular teeth bent outward from one of itsedges at their wider ends and merging into said edge at their narrowerends, their bodies growing thinner from their bends to their outer edgesand their rear ends being beveled.

11. A traction tire having triangular teeth bent outward from one of itsedges at their wider ends and merging into said edge at their narrowerends, their bodies growing thinner from their bends to their outer edgeand their rear ends being inclined to the rear of a radius.

12. A traction tire having triangular teeth bent outward from one of itsedges at their wider ends and merging into said edge at their narrowerends their bodies growing thinner from their bends to their outer edgesand their rear ends being beveled laterally and inclined radially to therear of a radius.

In testimony whereof I have hereunto subscribed my signature this the14th day of August, A. D. 1908.

CLARK STEPHENS.

itnesses M. H. BOWMAN, R. H. EMMoNs.

